Milia is an ace pilot, a female of the giant race of warriors known as the Zentradi (Meltlandi in The Super Dimension Fortress Macross: Do You Remember Love?). Serving on board an all-female ship, she joined Commander Vrlitwhai Kridanik's investigation of the "micrones" of Earth, and their spacecraft, the SDF-1 Macross. After being beaten in a pitched battle against the human pilot Maximilian Jenius, she volunteered for micloning and, reduced to human size, infiltrated the Macross. Rather than espionage, her real aim was to find and kill the man who had humiliated her, but when he defeated her in a knife fight and yet would not harm her, she realised that the emotion he had awoken in her was not hate, but love.

After defecting to the Macross and marrying Max, Milia was allowed to become a member of the UN Spacy in her own right and piloted a red-painted VF-1J Valkyrie Fighter into battle thereafter as her husband's wingmate. However, caring for her own people, she convinced Max and the other pilots to capture, rather than kill, their Zentradi opponents. This deed actually saved the ship during an all out attack by her race to destroy the ship as it, among other events, led to mutiny in the Zentradi forces severe enough for Commander Vrlitwhai to call a cease fire. The birth of her first child was another profoundly moving event for her when the artificially gestated woman realized that she created life with her own body.

In the original Macross series, Milia is a very prolific mother, and she and Max together have seven natural daughters and adopt a Zentradi girl over a period of twenty years from 2011 to 2030, the oldest being Komilia Maria Fallyna and the youngest being Mylene Flare. Her second pregnancy was apparently very difficult and nearly killed her.

In Macross 7 Milia sports a new short hairdo rather than her original long hair in Macross. Like Max, she doesn't seem to have aged. However, she is sensitive whenever people, especially Basara Nekki refer to her age. Milia is elected overwhelmingly as the mayor of City 7, largest ship of the Macross 7 colonization fleet, and is accompanied by Mylene, her daughter, who lives separately. Max is also present as commander of the Macross 7 fleet, although the couple are now separated. It is also implied that she still may have feelings for her estranged husband. As City 7's Mayor, Milia is determined not only to maintain law and order among her citizens, but to marry off the rebellious Mylene as well. It turns out that, like Max, her skills have not faltered after so many years, and she can still fly a Valkyrie as well as or better than anyone in the Macross 7 fleet. In the series, Milia still possesses her red VF-1J Valkyrie, which she pilots as passionately as she did in the original Super Dimension Fortress Macross. Milia also clearly shows signs of affection towards her antique red VF-1J when her Valkyrie, piloted by Gamlin Kizaki was destroyed by Sivil.

Later in the series, Milia, while serving as City 7's mayor, would from time-to-time pilot her Valkyrie - first piloting her VF-1J and gradually moving on to more advanced Valkyries, the VF-17D Nightmare and VF-22S Sturmvogel II respectively, all of which are colored a deep red - to assist the battle of the Macross 7 fleet against the Protodeviln. In the final episode of Macross 7, Milia and Max fought side-by-side with each other against Lord Geperuniti.